MK5 2.0CR to MK5 2.5L Swap DIY - WIRING GURUS NEDED!!

Strider17

Veteran Member
Joined
Apr 5, 2016
Location
Hamilton, Ontario, Canada
TDI
Beetle(sold) MK4 Golf TDI(sold) Mk4 Jetta TDI(parted out) MK4 Golf GTI w/ALH swap (built then parted out) 2015 Passat TDI Highline (current)
Figured out the fuel pump codes too

I plugged in my vcds, went to the central electrical module, went to Long coding and there is an option that was checked off something to do with a fuel pump (gasoline only). I unchecked that and the code went away.

I am still going over all the wiring to see if everything is wired up correctly before I wrap it all up

But looks like I am finally done.
 

Strider17

Veteran Member
Joined
Apr 5, 2016
Location
Hamilton, Ontario, Canada
TDI
Beetle(sold) MK4 Golf TDI(sold) Mk4 Jetta TDI(parted out) MK4 Golf GTI w/ALH swap (built then parted out) 2015 Passat TDI Highline (current)
With regards to the fuel pump relays for the TDI (double 449):

TDI pins 3 & 32 (2.5l pins 1 & 6) go to fusebox C fuse 27 (15A)

TDI pins 1 & 12 (2.5l pins 3 & 8) go to fusebox B fuse 15 (5A). Fuse 15 also feeds the glow plug control module pin 6 (as you noted)

NOTE: on the 2.5l, pin 3 was/is connected to fusebox C fuse 2 (5A) via a black/violet wire.

TDI pin 5 (2.5l pin 2) goes to the transfer pump in the tank

TDI pin 52 (2.5l pin 7) goes to the auxiliary fuel pump pin 2 on the engine

NOTE THAT PINS 2 & 7 ON THE 2.5l ARE CONNECTED TOGETHER IN THE WIRING HARNESS AND YOU WILL NEED TO SEPARATE THEM OR RUN A SEPARATE WIRE TO THE AUXILLIARY FUEL PUMP IF USING THE 2.5l HARNESS

TDI pin 2 (2.5l pin 5) goes to pin 46 on the 94 pin ECU connector

TDI pin 22 (2.5l pin 10) goes to pin 15 on the 60 pin ECU connector

The actual wire colours don't matter, just make sure they're connected as I have listed according to the wiring diagrams.

Basically the TDI uses the two 449 relays independently to run the tank and auxilliary fuel pumps via ECU control (ECU pins 46 & 15).

Whereas the 2.5l uses them in parallel to run the tank fuel pump and the high side of the injectors via the ECU & Vehicle Electrical System Control Module.
 

dieselherb1

Veteran Member
Joined
Oct 25, 2008
Location
Va.
TDI
06 MK5,09 Mk5 CR,03 Mk4,96,2-97 B4s,98 A3,2000 A4,4 Caddies( 2-1.6TD,1.6,TDI) Chevys 6.2,6.5,6.5TD
I talked with you last about your swap. I'm doing a CR into a 06 MK5 tdi. Have everything wired( I think) have it running but in limp mode. Any thoughts?
 
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